Single exposed plastic relief image printing plate washer

ABSTRACT

An apparatus for washing away the water soluble areas of a plastic emulsion covering a plate used in printing operations. Portions of the normally water soluble plastic emulsion become insoluble in water when exposed to actinic or ultraviolet light through a light dark master. The apparatus of the invention consists of a housing wherein water is sprayed uniformly over a printing plate by an arrangement of nozzles to remove the portions of the plastic emulsion remaining water soluble. The nozzles reciprocate to uniformly spray all areas of the emulsion coating, developing thereon, in plastic relief, a representation of the light dark master. The reciprocating nozzles also cyclically apply heated air to the developed plate. The printing plate is releasably maintained within the apparatus housing by adjustable spring clamps which secure the corners of the printing plate to a wash surface on a door of the housing.

llnited States Patent 1 91 Bunker 1451 May 1,1973

[ 1 SINGLE EXPOSED PLASTIC RELIEF IMAGE PRINTING PLATE WASHER Richard D.Bunker, Salt Lake City, Utah [75] Inventor:

22 Filed: Jan. 3, 1972 21 Appl, No.: 214,575

3,133,491 5/1964 Shaw et al. .....95/IO0 638.916 12/1899 Doyle ..95/100X 2,755,716 7/1956 Epstein.... ....95/89 R 3,528,358 9/1970 Pickard..95/89 R FOREIGN PATENTS OR APPLICATIONS 1,040,86] 9/1966 Great Britain..95/89 R 692,498 8/1964 Canada ..95/89 R Primary ExaminerSamuel S.Matthews Assistant Examiner-Fred L. Braun Attorney-B. Deon Criddle [57]ABSTRACT An apparatus for washing away the water soluble areas of aplastic emulsion covering a plate used in printing operations. Portionsof the normally water soluble plastic emulsion become insoluble in waterwhen exposed to actinic or ultraviolet light through a light darkmaster. The apparatus of the invention consists of a housing whereinwater is sprayed uniformly over a printing plate by an arrangement ofnozzles to remove the portions of the plastic emulsion remaining watersoluble. The nozzles reciprocate to uniformly spray all areas of theemulsion coating, developing thereon, in plastic relief, arepresentation of the light dark master. The reciprocating nozzles alsocyclically apply heated air to the developed plate. The printing plateis releasably maintained within the apparatus housing by adjustablespring clamps which secure the corners of the printing plate to a washsurface on a door of the housing.

3 Claims, 7 Drawing Figures Patented Ma 1, 1973 3,730,069

2 Sheets-Sheet l Ila SINGLE EXPOSED PLASTIC RELIEF IMAGE PRINTING PLATEWASHER BRIEF DESCRIPTION OF THE INVENTION 1. Field of the Invention Thisinvention relates to apparatus for washing away the water solubleportions of an exposed plastic printing plate.

2. Prior Art The present invention is intended to be used particularlywith plastic image printing plates of the type disclosed in my copendingapplication for U.S. Pat. Ser. No. 80,250, filed Oct. 12, l970. Prior tothe present invention, to the best of my knowledge, there has not beenknown a water washing apparatus suitable for continuously and completelywashing such plates.

SUMMARY OF THE INVENTION It is a principal object of the presentinvention to provide a low cost, reliable and efficient washingapparatus for removing the water soluble areas of the plastic emulsioncovered printing plate of the type disclosed in my aforesaid applicationfor United States Patent.

Another object is to provide means within the apparatus for the removalof water collected on the developed plate.

Another object is to provide an apparatus having means associatedtherewith for automatically controlling printing plate washing anddrying operations within the apparatus of the invention.

Still another object is to provide means for easily and releasablysecuring a printing plate within the apparatus of the invention.

Principal features of the invention include a housing with a hingedaccess door through a front wall thereof. The inner face of the doorserves as a wash surface and has adjustable, swiveling, spring clampsthereon to releasably secure an exposed plastic emulsion coveredprinting plate. Within the housing a rack of nozzles is arranged toreciprocate on tracks and to spray water or air uniformly towards thewash surface. The nozzles are staggered to uniformly spray the entiresurface of 'a plate on the wash surface as the rack is moved by an armarrangement back and forth in front of the plate.

A single flexible line, having one end connected to the rack of nozzles,has its other end coupled to two valve controlled water or air linesthat alternately supply either water or heated compressed air. Timersalternately open the valve in the passing water line, then after apre-set wash period closes that valve and opens the valve in the airline to allow passage of heated compressed air through the flexible lineand nozzles. Thereafter, the valve in the air line is closed, stoppingheated air flow, the drive motor for the rack is turned off and an airheater through which the compressed air is directed prior to its passagethrough the second valve is turned off.

A drain is provided leading from the bottom of the housing to carry offwash water and an air temperature control switch, the timers for thewater and heated compressed air cycles, start stop buttons, and aprogrammer switch are all located on a control panel at the front of thehousing.

Additional objects and features of the invention will become apparentfrom the following detailed description and drawings disclosing what ispresently contemplated as being the best mode of the invention.

THE DRAWINGS FIG. 1 is a perspective view of the invention shown fromthe one side and slightly above the housing;

FIG. 2, a vertical section view taken on the line 2-2 of FIG. 1;

FIG. 3, a rear elevation view of the invention with a housing accesspanel partially broken away to expose the interior components;

FIG. 4, a horizontal section view taken on the line 44 of FIG. 2; I

FIG. 5, a vertical section view taken on the line 55 of FIG. 2 andshowing the reciprocating spray nozzle arrangement of the invention;

FIG. 6, a vertical section view taken on the line 66 of FIG. 2, showingthe inner face of the housing door on which are mounted adjustableswivelling spring clamps, whereby the door face becomes a wash surface;and

FIG. 7, an enlarged view, taken on the line 7-7 of FIG. 6, and showing aspring clamp and the mounting therefore.

' DETAILED DESCRIPTION Referring now to the drawings:

In the illustrated preferred embodiment, the cyclic plastic relief imageprinting plate washing apparatus, shown generally at 10, includes ahousing 11, supported on legs 11a, having an access panel 12 forming arear face thereof and with a door 13, pivotally mounted at 14 providingaccess through the housing front face. Door 13 has a handle 13a mountedthereon forming part of a latch 1312, FIG. 6, that can be turned intoengagement with housing 11 such that the door 13 is sealed to thehousing. A resilient seal 15 extends peripherally around the inside ofdoor 13 to insure complete watertight sealing of the door with housing 11.

As best seen in FIG. 6, door 13 has adjustable spring clamps 16 mountedon its inner face. The spring clamps each consist of a block 17 havingone end of a hairpin spring 18 extending therethrough and bent as shownat 18a, FIG. 7, to keep it from being pulled through and the other end18b of the spring in engagement with the inner face of door 13. Eachblock 17 slides along a square cross-sectional rod 19 that is insertedtherethrough such that blocks 17 can be moved towards or away from eachother to accommodate plastic printing plates of various widths. The endsof rods 19 are fitted into sleeves 20 that are slidably mounted onstraps 21 which have their ends respectively attached by screws 21a tothe top and bottom of door 13. Thus, rods 19 can slide towards or awayfrom each other to accommodate plastic printing plates of variouslengths. Set screws 20a, threaded into sleeves 20, when turned into thesleeves 20 engage the straps 21 locking the sleeves thereto.

An exposed plastic printing plate is developed in the plate washingapparatus 10 by positioning it on the wash surface and positioning theends 18b of the springs 18 over the corners of the plate. Door 13 isthen closed and latched, thereby positioning the printing plate directlyopposite to a reciprocating nozzle rack 22.

Nozzle rack 22 consists of a pair of .tubes 23 interconnected at theirends to be continuous, and spaced nozzles 24 projecting from the tubes.A flexible line 25 is connected to a top portion of the continuous tubes23, and supplies either water or heated compressed air to the nozzles 24in a manner to be hereinafter described in detail.

Brackets 26 and 27 are clamped to tubes 23 by straps 28a and 28b andbolts and nuts 29a and 29b. Bracket 26 has top and bottom grooved wheels30 and 31 journaled thereto and arranged to roll freely above and below,respectively, on a round rod 32 that is fixed between opposite sidewalls of housing 11. Another rod 34 has its ends fixed between thehousing sides to serve as a guide track on which grooved wheels 33journaled to bracket 27, roll.

As shown best in FIG. 5, nozzle rack 22 is reciprocated by back andforth movements of the upper end 35a of an arm 35. Arm 35 has its lowerend 35b pivotally connected at 36 to the bottom of housing 11. The upperend 35a of arm 35 has a slot 37 formed therein, through which a bolt 29ais fitted to loosely secure arm end 35a between strap 28a and bracket26. As arm 35 is oscillated back and forth around pivot connection 36travel of bolt 29a within slot 37 reciprocates rack 22 back and forth.Arm 35 is pivotally connected intermediate pivot connection 36 and slot37, at 38, to one end 39a of a drive arm 39. The other end 39b of arm 39is pivotally connected at 40 to the end 41a of a short linkage arm 41,the other end 41b of which is fixed to the output shaft ofa motor 42,shown best in FIG. 2. As the output shaft of motor 42 turns, linkageshort arm 41 is rotated, thereby turning the pivot connection 40 andreciprocating drive arm 39 to oscillate arm 35.

Water or heated compressed air is supplied to the nozzle rack 22 throughthe flexible line 25. The flexible line, FIG. 4, is connected through atee 43 to an air line 44 and to a water line 45. Valves 46 and 47 arepositioned in lines 44 and 45, respectively, to control flowtherethrough. The operation of valves 46 and 47 is controlled, as willbe hereinafter explained, by timers that alternately allow water and airto flow through flexible line 25. A coupling 48 is provided on the endof water line opposite tee 43 for connection to a water source, notshown. Compressed air is introduced into the washing apparatus 10through a coupling 49 connected to a source, not shown, line 50, an airheater 51, air line 44, valve 46, the flexible line 25 and rack 22. Thetemperature to which air is raised within air heater 51 is controlled bya thermostat 53, mounted to a control panel 52, on the front of housing11, above door 13.

Control panel 52 also contains other control and programming means thatregulate the operations of the plate washing apparatus 10. As best shownin FIG. 5, the control and programming means consists of thethermostatic control 53, which controls the heating of compressed air inair heater 51, a washer timer 54, and a drying timer 55. Washer timer 54programs the opening and closing of valve 47 to regulate water flowthrough the nozzles 24 of the nozzle rack 22 to wash away portions of aprinting plate emulsion. Drying timer 55 operates alternately withwasher timer 54 and when valve 47 is closed to open valve 46 so thatcompressed air will be distributed through nozzles 24. Drying timer 55also regulates on-off operation of the air heater 51,'with the heatlevel of the heater being controlled by the thermostatic control 53.Start button 56 and stop button 57 are also provided on panel 52 tocontrol electrical power to the washer apparatus and to start and stopthe motor 42 that reciprocates nozzle rack 22. Stop button 57 iselectrically connected through a programmer switch 58 to timers S4 and55 such that when a timer runs out completing a cycle, as controlled byprogrammer switch 58, the stop button mechanism is activated, turningoff electrical power to the apparatus. Programmer switch 58 is a twoposition switch whose positioning electrically connected to provideeither a cycle of operation having both a wash and a dry cycle, or adrying cycle alone. The controls on control panel 52 allow the apparatusto be pre-set for automatic developing of an exposed plastic reliefimage printing plate positioned on the wash surface and allow theapparatus to be set to include additional drying cycles should the platebeing developed not be completely dried in a normal wash dry cycle.

Although a preferred form of my invention has been herein disclosed, itis to be understood that the present disclosure is made by way ofexample and that variations are possible without departing from thescope of the hereinafter claimed subject matter, which subject matter Iregard as my invention.

I claim: 1. A cyclic, exposed plastic relief image printing plate washercomprising a housing; a door providing access to the interior of thehousing; means on an inner face of the door for clamping a printingplate thereto, said means comprising sets of blocks with each setmounted to be moved in two directions normal to one another and with thesets being movable parallel to one another, and hairpin springs eachhaving one end pivotally mounted in one of said blocks and its other endbiased towards the inner surface of the door whereby a printing platepositioned between the spring and the door is securely held in place tobe washed; nozzle means within 'the housing through which water and airare alternately sprayed against an entire exposed surface of saidprinting plate; and

means for alternately supplying the water and air through said nozzlemeans.

2. A cyclic, exposed plastic relief image printing plate washer asrecited in claim 1, wherein the nozzle means includes a nozzle rackhaving wheels journaled thereto; and including rails mounted betweensides of the housing to serve as guide tracks for said wheels; and

means for reciprocating said nozzle rack, said reciprocating meanscomprising a motor,

a linkage arm having one end connected to being turned by the motor,

a driver arm having one end pivotally connected to the other end of thelinkage arm, and

an oscillating arm pivotally connected at one end to the housing andpivotally connected intermediate its ends to the other end of the driverarm, said oscillating arm having a slot in the other end thereof andpivot means extending through the slot and connected to the rack ofnozzles.

3. A cyclic, exposed plastic relief image printing plate as in claim 2,further including means for heating air supplied through the nozzles. 5

1. A cyclic, exposed plastic relief image printing plate washercomprising a housing; a door providing access to the interior of thehousing; means on an inner face of the door for clamping a printingplate thereto, said means comprising sets of blocks with each setmounted to be moved in two directions normal to one another and with thesets being movable parallel to one another, and hairpin springs eachhaving one end pivotally mounted in one of said blocks and its other endbiased towards the inner surface of the door whereby a printing platepositioned between the spring and the door is securely held in place tobe washed; nozzle means within the housing through which water and airare alternately sprayed against an entire exposed surface of saidprinting plate; and means for alternately supplying the water and airthrough said nozzle means.
 2. A cyclic, exposed plastic relief imageprinting plate washer as recited in claim 1, wherein the nozzle meansincludes a nozzle rack having wheels journaled thereto; and includingrails mounted between sides of the housing to serve as guide tracks forsaid wheels; and means for reciprocating said nozzle rack, saidreciprocating means comprising a motor, a linkage arm having one endconnected to being turned by the motor, a driver arm having one endpivotally connected to the other end of the linkage arm, and anoscillating arm pivotally connected at one end to the housing andpivotally connected intermediate its ends to the other end of the driverarm, said oscillating arm having a slot in the other end thereof andpivot means extending through the slot and connected to the rack ofnozzles.
 3. A cyclic, exposed plastic relief image printing plate as inclaim 2, further including means for heating air supplied through thenozzles.